module Aaa where

piDigits = g (1,0,1,1,3,3) where 
	g(q,r,t,k,n,l) = if 4*q+r-t<n*t 
		then n : g(10*q,10*(r-n*t),t,k,div(10*(3*q+r))t-10*n,l) 
		else g(q*k,(2*q+r)*l,t*l,k+1,div(q*(7*k+2)+r*l)(t*l),l+2)

process x = piDigits !! x

main = getLine >>= return . process . read  >>= print

